This application claims the benefit of Korean Patent Application No. 10-2011-0034523 filed on Apr. 14, 2011 and Korean Patent Application No. 10-2012-0025599 filed on Mar. 13, 2012. All of the contents disclosed in the description and drawings of this application are incorporated herein by reference.
Cone-shaped crushers are very important as crushers in aggregate and mineral processing industries. Various structures and types have been developed for a variety of uses.
International Patent Publication No. WO2009/065995 discloses a general structure of a cone-shaped crusher, and the cone-shaped crusher includes a frame having a cavity formed therein, a first crushing blade that is provided inside the frame, a main shaft that is eccentrically accommodated in the frame, a truncated cone-shaped crushing head that is coupled to an outer circumferential surface of the main shaft, a second crushing blade that covers the surface of the crushing head, an upper bearing part that is coupled to an upper end portion of the main shaft, a lower bearing part that is coupled to a lower end portion of the main shaft, and driving means that drives the main shaft so that the main shaft can perform a gyratory movement. Here, the first crushing blade is spaced apart at a proper distance from the second crushing blade mounted on an outer circumferential surface of the crushing head. Objects to be crushed that are put into the cone-shaped crusher are compressed and crushed when the gap between the first crushing blade and the second crushing blade that performs a gyratory movement along the main shaft becomes gradually narrow, and the crushed aggregate is discharged to the outside by repeating the falling process when the gap between the first crushing blade and the second crushing blade increases.
The above-described cone-shaped crusher adopts a spherical bearing as the upper bearing part. The spherical bearing includes a stationary part that is fixed to the frame and has an inner frictional surface formed spherically, and a movable part that is coupled to the upper end of the main shaft rotates while supported by the stationary part and has an outer frictional surface formed spherically.
However, as the above-described cone-shaped crusher is operated, the spherical bearing is worn out, and thus, a gap is generated between the stationary part and the movable part, and the upper end portion of the main shaft is not accurately supported in its originally designed state. Also, since the upper end portion of the main shaft is operated while being jolted by the gap, the wear of the spherical bearing is gradually accelerated. This phenomenon changes the eccentric angle of the main shaft, and if the main shaft performs a gyratory movement with the changed eccentric angle, the wear of the lower bearing coupled to the lower end portion of the main shaft may be accelerated, thereby causing the breakdown of the lower bearing.
Even if there is no problem in the lubricating system of the above-described cone-shaped crusher, if a person operating the cone-shaped crusher does not replace the upper bearing and the lower bearing at an accurate replacement time and uses the bearings slightly longer, then the cone-shaped crusher is greatly damaged, thereby causing huge repair costs.